The Common Core State Standards (CCSS), released by the National Governors Association and the Council of Chief State Schools Off icers in 2010, are the culmination of at least 25 years of emphasis on systemic school reform, using high-stakes assessments as a lever to improve the achievement of American schoolchildren. To help readers understand both the challenges and the possibilities, this article looks at where the CCSS came from, their strengths and weaknesses, and how as a profession we can best respond to the challenges they pose.